Publications

We present two algorithms that use membership and equivalence queries to exactly identify the concepts given by the union of s discretized axis-parallel boxes in d-dimensional discretized Euclidean space where there are n discrete values that each coordinate can have. The first algorithm receives at most sd counterexamples and uses time and membership queries polynomial in s and log n for d any constant. Further, all equivalence queries made can be formulated as the union of O(sd logs) axis-parallel boxes. Next, we introduce a new complexity measure that better captures the complexity of a union of boxes than simply the number of boxes and dimensions. Our new measure, u, is the number of segments in the target polyhedron where a segment is a maximum portion of one of the sides of the polyhedron that lies entirely inside or entirely outside each of the other halfspaces defining the polyhedron. We then present an improvement of our first algorithm that uses time and queries polynomial in u and log n. The hypothesis class used here is decision trees of height at most 2sd, Further we can show that the time and queries used by this algorithm are polynomial in d and log n for s any constant thus generalizing the exact learnability of DNF formulas with a constant number of terms. In fact, this single algorithm is efficient for either s or d constant.

This presentation (consisting of vugraphs) first provides the background motivation for Sandia`s effort for the development of improved crystalline silicon solar cells. It then discusses specific results and progress, and concludes with a brief discussion of options for next year.

This report describes the equipment required for initial assembly/maintenance and inspection/resetting of the Fifth Wheel system. It also gives a step-by-step procedure for initial assembly/maintenance inspection and procedures for resetting the system and Eager-Pac installation. The Fifth Wheel system is associated with a tractor-type vehicle used for materials handling.

High Consequence System Surety is an ongoing project at Sandia National Laboratories. This project pulls together a multi- disciplinary team to integrate the elements of surety into an encompassing process. The surety process will be augmented and validated by applying it to an automated system handling a critical nuclear weapon component at the Mason & Hanger Pantex Plant. This paper presents the development to date of an integrated, high consequence surety process.

Heavy Ion Backscattering Spectrometry (HIBS) is a new ion beam analysis tool using heavy, low-energy ions in backscattering mode which can detect very low levels of surface contamination. By taking advantage of the greatly increased scattering cross-section for such ion beams and eliminating unwanted substrate scattering with a thin carbon foil, our research system has achieved a sensitivity ranging from {approximately}5{times}10{sup 10} atoms/cm{sup 2} for Fe to {approximately}1{times}10{sup 9} atoms/cm{sup 2} for Au on Si, without preconcentration. A stand-alone HIBS prototype now under construction in collaboration with SEMATECH is expected to achieve detection limits of {approximately}5{times}10{sup 9} atoms/cm{sup 2} for Fe and {approximately}1{times}10{sup 8} atoms/cm{sup 2} for Au on Si, again without preconcentration. Since HIBS is standardless and has no matrix effects, it will be useful not only as a standalone tool, but also for benchmarking standards for other tools. This conference is testimony to the importance of controlling contamination in microelectronics manufacturing. By the turn of the century, very large scale integrated circuit processing is expected to require contamination levels well below 1{times}10{sup 9} atoms/cm{sup 2} in both starting materials and introduced by processing. One of the most sensitive of existing general-purpose tools is Total reflection X-Ray Fluorescence (TXRF), which can detect {approximately}1{times}10{sup 10} atoms/cm{sup 2} levels of some elements such as Fe and Cu, but for many elements it is limited to 1{times}10{sup 12} atoms/cm{sup 2} or worse. TXRF can achieve a sensitivity of 10{sup 8} atoms/cm{sup 2} through the use of synchrotron radiation or via pre-concentration using Vapor Phase Decomposition. HIBS provides an ion beam analysis capability with the potential for providing similar sensitivity at medium Z and higher sensitivity at larger Z, all without pre-concentration or matrix effects.

We report the results of to separate long-term tests of batteries and charge controllers in small stand-alone PV systems. In these experiments, seven complete systems were tested for two years at each of two locations: Sandia National Laboratories in Albuquerque and the Florida Solar Energy Center in Cape Canaveral, Florida. Each system contained a PV array, flooded-lead-acid battery, a charge controller and a resistive load. Performance of the systems was strongly influenced by the difference in solar irradiance at the two sites, with some batteries at Sandia exceeding manufacturer`s predictions for cycle life. System performance was strongly correlated with regulation reconnect voltage (R{sup 2} correlation coefficient = 0.95) but only weakly correlated with regulation voltage. We will also discuss details of system performance, battery lifetime and battery water consumption.

A model is presented which describes the formation of surface damage ``gouging`` on the rails that guide rocket sleds. An unbalanced sled can randomly cause a very shallow-angle, oblique impact between the sled shoe and the rail. This damage phenomenon has also been observed in high-velocity guns where the projectile is analogous to the moving sled shoe and the gun barrel is analogous to the stationary rail. At sufficiently high velocity, the oblique impact will produce a thin hot layer of soft material on the contact surfaces. Under the action of a normal moving load, the soft layer lends itself to an anti-symmetric deformation and the formation of a ``hump`` in front of the moving load. A gouge is formed when this hump is overrun by the sled shoe. The phenomenon is simulated numerically using the CTH strong shock physics code, and the results are in good agreement with experimental observation.

The objective of this paper is to provide a general overview of hydrologic conditions at the Waste Isolation Pilot Plant (WIPP) by describing several key hydrologic studies that have been carried out as part of the site characterization program over the last 20 years. The paper is composed of three parts: background information about general objectives of the WIPP project; information about the geologic and hydrologic setting of the facility; and information about three aspects of the hydrologic system that are important to understanding the long-term performance of the WIPP facility. For additional detailed information, the reader is referred to the references cited in the text.

Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. The more overburden removed by explosives, the less blasted material there is left to be transported with mechanical equipment, such as draglines and trucks. In order to optimize the percentage of rock that is cast, a higher powder factor than normal is required plus an initiation technique designed to produce a much greater degree of horizontal muck movement. This paper compares two blast models known as DMC (Distinct Motion Code) and SABREX (Scientific Approach to Breaking Rock with Explosives). DMC, applies discrete spherical elements interacted with the flow of explosive gases and the explicit time integration to track particle motion resulting from a blast. The input to this model includes multi-layer rock properties, and both loading geometry and explosives equation-of-state parameters. It enables the user to have a wide range of control over drill pattern and explosive loading design parameters. SABREX assumes that heave process is controlled by the explosive gases which determines the velocity and time of initial movement of blocks within the burden, and then tracks the motion of the blocks until they come to a rest. In order to reduce computing time, the in-flight collisions of blocks are not considered and the motion of the first row is made to limit the motion of subsequent rows. Although modelling a blast is a complex task, the DMC can perform a blast simulation in 0.5 hours on the SUN SPARCstation 10--41 while the new SABREX 3.5 produces results of a cast blast in ten seconds on a 486-PC computer. Predicted percentage of cast and face velocities from both computer codes compare well with the measured results from a full scale cast blast.

The Mixed Waste Landfill Integrated Demonstration (MWLID) focuses on ``in-situ`` characterization, monitoring, remediation, and containment of landfills in and environments that contain hazardous and mixed waste. The MWLID mission is to assess, demonstrate, and transfer technologies and systems that lead to faster, better, cheaper, and safer cleanup. Most important, the demonstrated technologies will be evaluated against the baseline of conventional technologies. Key goals of the MWLID are routine use of these technologies by Environmental Restoration Groups throughout the DOE complex and commercialization of these technologies to the private sector. The MWLID is demonstrating technologies at hazardous waste landfills located at Sandia National Laboratories and on Kirtland Air Force Base. These landfills have been selected because they are representative of many sites throughout the Southwest and in other and climates.

This paper addresses the issues surrounding the use of NIAM to capture time dependencies in a domain of discourse. The NIAM concepts that support capturing time dependencies are in the event and process portions of the NIAM metamodel, which are the portions most poorly supported by a well-established methodology. This lack of methodological support is a potentially serious handicap in any attempt to apply NIAM to a domain of discourse in which time dependencies are a central issue. However, the capability that NIAM provides for validating and verifying the elementary facts in the domain may reduce the magnitude of the event/process-specification task to a level at which it could be effectively handled even without strong methodological support.

A statistical design of experiments approach has been employed to evaluate the particle removal efficacy of the SC-1/megasonic clean for sub-0.15 {mu}m inorganic particles. The effects of megasonic input power, solution chemistry, bath temperature, and immersion time have been investigated. Immersion time was not observed to be a statistically significant factor. The NH{sub 4}OH/H{sub 2}O{sub 2} ratio was significant, but varying the molar H{sub 2}O{sub 2} concentration had no effect on inorganic particle removal. Substantially diluted chemistries, performed with high megasonic input power and moderate-to-elevated temperatures, was shown to be very effective for small particle removal. Bath composition data show extended lifetimes can be obtained when high purity chemicals are used at moderate (eg., 45{degrees}C) temperature. Transition metal surface concentrations and surface roughness have been measured after dilute SC-1 processing and compared to metallic contamination following traditional SC-1.

I{sub DDQ} testing is mandatory to ensure that low power CMOS ICs meet their design intent. I{sub DDQ} testing is both a design verifier for low quiescent current and a sensitive production test for defects. Quiescent power reduction is particularly important for products such as cardiac pacemakers, laptop computers, and cellular telephones.

Transformers of two different designs; and unencapsulated pot core and an encapsulated toroidal core have been modeled for circuit analysis with circuit simulation tools. We selected MicroSim`s PSPICE and Anology`s SABER as the simulation tools and used experimental BH Loop and network analyzer measurements to generate the needed input data. The models are compared for accuracy and convergence using the circuit simulators. Results are presented which demonstrate the effects on circuit performance from magnetic core losses, eddy currents, and mechanical stress on the magnetic cores.

A new waveguide is designed using a cut-off slab waveguide for fabrication of single-mode rib optical waveguides with mesa isolation. These waveguides are easy to fabricate and offer crosstalk performance perhaps better than BH waveguides.

Developing the ability to recognize a landmark from a visual image of a robot`s current location is a fundamental problem in robotics. The authors consider the problem of PAC-learning the concept class of geometric patterns where the target geometric pattern is a configuration of k points in the real line. Each instance is a configuration of n points on the real line, where it is labeled according to whether or not it visually resembles the target pattern. They relate the concept class of geometric patterns to the landmark recognition problem and then present a polynomial-time algorithm that PAC-learns the class of one-dimensional geometric patterns when the negative examples are corrupted by a large amount of random misclassification noise.

A series of experiment were conducted to study the influence of electrode geometry on the prebreakdown (and breakdown) characteristics of high resistivity ({rho} > 30 k{Omega}-cm), p-type Si wafers under quasi-uniform and non-uniform electric field configurations. In the quasi-uniform field configuration, the 1mm thick Si wafer was mounted between the slots of two plane parallel stainless steel disc electrodes (parallel), while the non-uniform field was obtained by mounting the wafer between two pillar-type electrodes with a hemispherical tip (pillar). The main objective of the above investigation was to verify if the uniform field configuration under a parallel system has a positive influence by reducing the field enhancement at the contact region, as opposed to the definite field enhancement present in the case of the non-uniform pillar system. Also, it was proposed to study the effect of the contact profile on the field distribution over the wafer surface and hence its influence on the high-field performance of the Si wafers.

The current baseline plan for RH TRU (remote-handled transuranic) waste disposal is to package the waste in special canisters for emplacement in the walls of the waste disposal rooms at the Waste Isolation Pilot Plant (WIPP). The RH waste must be emplaced before the disposal rooms are filled by contact-handled waste. Issues which must be resolved for this plan to be successful include: (1) construction of RH waste preparation and packaging facilities at large-quantity sites; (2) finding methods to get small-quantity site RH waste packaged and certified for disposal; (3) developing transportation systems and characterization facilities for RH TRU waste; (4) meeting lag storage needs; and (5) gaining public acceptance for the RH TRU waste program. Failure to resolve these issues in time to permit disposal according to the WIPP baseline plan will force either modification to the plan, or disposal or long-term storage of RH TRU waste at non-WIPP sites. The recommended strategy is to recognize, and take the needed actions to resolve, the open issues preventing disposal of RH TRU waste at WIPP on schedule. It is also recommended that the baseline plan be upgraded by adopting enhancements such as revised canister emplacement strategies and a more flexible waste transport system.

Sandia National Laboratories manages the US Department of Energy program for slimhole drilling. The principal objective of this program is to expand proven geothermal reserves through increased exploration, made possible by lower-cost slimhole drilling. For this to be a valid exploration method, however, it is necessary to demonstrate that slimholes yield enough data to evaluate a geothermal reservoir, and that is the focus of Sandia`s current research. Sandia negotiated an agreement with Far West Capital, which operates the Steamboat Hills geothermal field, to drill and test an exploratory slimhole on their lease. The principal objectives for the slimhole were development of slimhole testing methods, comparison of slimhole data with that from adjacent production-size wells, and definition of possible higher-temperature production zones lying deeper than the existing wells.

Emphasis on the human-to-aircraft interface has magnified in importance as the performance envelope of today`s aircraft has continued to expand. A major problem is that there has been a corresponding increase in the need for better fitting protection equipment and unfortunately it has become increasingly difficult for aircrew members to find equipment that will provide this level of fit. While protection equipment has, historically had poor fit characteristics, the issue has grown tremendously with the recent increase in the numbers of minorities and women. Fundamental to this problem are the archaic methods for sizing individual equipment and the methods for establishing a sizing system. This paper documents recent investigations by the author into developing new methods to overcome these problems. Research centered on the development of a new statistically based method for describing form and the application of fuzzy clustering using the new shape descriptors. A sizing system was developed from the application of the research, prototype masks were constructed and the hardware tested under flight conditions.

Internal corrosion in semiconductor gas delivery systems may lead to increased particle counts in downstream fabrication tools and to catastrophic failure of the delivery system itself. The problem is particularly acute since, once the corrosion begins, it becomes a moisture reservoir to further damage the system. To keep gas systems as moisture free as possible semiconductor manufacturers employ drying filters, usually located just after the source of the process gas. Even so, the piping for corrosive gases may need to be rebuilt every few years. Careful monitoring of the moisture in the process gases can provide valuable information about the state of the gas handling system and its effect on the process integrity. Presently there are several technologies costing $50K or less that are capable of detecting trace water vapor as low as 50 ppb in N{sub 2}. However, no one type of instrument has achieved universal acceptance. In particular, all have limited compatibility with corrosive gases such as HCl and HBr. The goal of this project is to develop an in-line instrument based on infrared spectroscopy for this purpose. Earlier results leave no doubt that FTIR spectroscopy can be successfully used for trace water detection. However, important questions regarding optimal data analysis and instrument design are not yet fully answered. It is the goal of this research effort to answer these questions and to incorporate the findings into a prototype device suitable for commercialization.

A description of the flow field in an overflow wafer rinse process is presented. This information is being used in an initiative whose principal objective is to reduce the usage of water in wafer rinsing. The velocity field is calculated using finite-element numerical techniques. A large portion of the water does not contribute to wafer rinsing.

Photovoltaic (PV) modules and photovoltaic balance of systems equipment are designed, manufactured, and marketed internationally. Each country or group Of countries has a set of electrical safety codes, either in place or evolving, that guide and regulate the design and installation of PV power systems. A basic difference in these codes is that some require hard (low-resistance) grounding (the United States and Canada) and others opt for an essentially ungrounded system (Europe and Japan). The significant design and safety issues that exist between the two grounding concepts affect the international PV industry`s ability to economically and effectively design and market safe, reliable, and durable PV systems in the global market place. This paper will analyze the technical and safety benefits, penalties, and costs of both grounded arid ungrounded PV systems. The existing grounding practice in several typical countries will be addressed.

Conservatively, there are 100,000 localities in the world waiting for the benefits that electricity can provide, and many of these are in climates where sunshine is plentiful. With these locations in mind a prototype 30 kW hybrid system has been assembled at Sandia to prove the reliability and economics of photovoltaic, diesel and battery energy sources managed by an autonomous power converter. In the Trimode Power Converter the same power parts, four IGBT`s with an isolation transformer and filter components, serve as rectifier and charger to charge the battery from the diesel; as a stand-alone inverter to convert PV and battery energy to AC; and, as a parallel inverter with the diesel-generator to accommodate loads larger than the rating of the diesel. Whenever the diesel is supplying the load, an algorithm assures that the diesel is running at maximum efficiency by regulating the battery charger operating point. Given the profile of anticipated solar energy, the cost of transporting diesel fuel to a remote location and a five year projection of load demand, a method to size the PV array, battery and diesel for least cost is developed.

Ceramics offer significant performance advantages over other engineering materials in a great number of applications such as turbocharger rotors and wear components. However, to realize their full market potential, ceramics must become more cost competitive. One way to achieve such competitiveness is to maximize manufacturing yield via process optimization. One simple optimization strategy involves maximizing yield by decreasing product variability (e.g., by operating in a regime that is inherently process tolerant). This paper extends this concept to the simultaneous optimization of many material characteristics, which is more typical of the requirements of a real ceramic manufacturing operation.

Extensive simulations of Tokamak disruptions have provided a picture of material erosion that is limited by the transfer of energy from the incident plasma to the armor solid surface through a dense vapor shield. Radiation spectra were recorded in the VUV and in the visible at the Efremov Laboratories on VIKA using graphite targets. The VUV data were recorded with a Sandia Labs transmission grating spectrograph, covering 1--40 nm. Plasma parameters were evaluated with incident plasma energy densities varying from 1--10 kJ/cm{sup 2}. A second transmission grating spectrograph was taken to 2MK-200 at TRINITI to study the plasma-material interface in magnetic cusp plasma. Target materials included POCO graphite, ATJ graphite, boron nitride, and plasma-sprayed tungsten. Detailed spectra were recorded with a spatial resolution of {approximately}1 mm resolution. Time-resolved data with 40--200 ns resolution was also recorded. The data from both plasma gun facilities demonstrated that the hottest plasma region was sitting several millimeters above the armor tile surface.

In the past few years much effort has been devoted to finding faster and more convenient ways to exchange data between nodes of massively parallel distributed memory machines. One such approach, taken by Thorsten von Eicken et al. is called Active Messages. The idea is to hide message passing latency and continue to compute while data is being sent and delivered. The authors have implemented Active Messages under SUNMOS for the Intel Paragon and performed various experiments to determine their efficiency and utility. In this paper they concentrate on the subset of the Active Message layer that is used by the implementation of the Split-C library. They compare performance to explicit message passing under SUNMOS and explore new ways to support Split-C without Active Messages. They also compare the implementation to the original one on the Thinking Machines CM-5 and try to determine what the effects of low latency and low band-width versus high latency and high bandwidth are on user codes.

SUNMOS is an acronym for Sandia/UNM Operating System. It was originally developed for the nCUBE-2 MIMD supercomputer between January and December of 1991. Between April and August of 1993, SUNMOS was ported to the Intel Paragon. This document provides a quick overview of how to compile and run jobs using the SUNMOS environment on the Paragon. The primary goal of SUNMOS is to provide high performance message passing and process support an example of its capabilities, SUNMOS Release 1.4 occupies approximately 240K of memory on a Paragon node, and is able to send messages at bandwidths of 165 megabytes per second with latencies as low as 42 microseconds using Intel NX calls. By contrast, Release 1.2 of OSF/1 for the Paragon occupies approximately 7 megabytes of memory on a node, has a peak bandwidth of 65 megabytes per second, and latencies as low as 42 microseconds (the communication numbers are reported elsewhere in these proceedings).

Sandia National Laboratories became seriously involved in the science education reform movement in 1989 in response to a Department of Energy directive: ``We must expand our involvement in science education to inspire the youth of American to either enter or feel more comfortable in the fields of math, science and engineering. With our labs and facilities we are uniquely well positioned to provide major assistance in strengthening science and engineering motivation and education, making it `come alive` for the main body of students who too often fear these disciplines or who cannot relate to them``. (Adm. James D. Watkins, U.S. Sec`t. of Energy, 9/5/89)

Functioning, matrixed, field emission devices have been fabricated using a modification of standard integrated circuit fabrication techniques. The emitter-to-gate spacing is fixed by the thickness of a deposited oxide and not by photolithographic techniques. Modeling of the emitted electron trajectories using a two dimensional, Poisson solver, finite difference code indicates that much of the current runs perpendicular to plane of the part. Functioning triode structures have been fabricated using this approach. Emission current, to a collector electrically and physically separated from the matrixed array follows Fowler-Nordheim behavior.

Market-place acceptance of utility-connected photovoltaic (PV) power generation systems and their accelerated installation into residential and commercial applications are heavily dependent upon the ability of their power conditioning subsystems (PCS) to meet high reliability, low cost, and high performance goals. Many PCS development efforts have taken place over the last 15 years, and those efforts have resulted in substantial PCS hardware improvements. These improvements, however, have generally fallen short of meeting many reliability, cost and performance goals. Continuously evolving semiconductor technology developments, coupled with expanded market opportunities for power processing, offer a significant promise of improving PCS reliability, cost and performance, as they are integrated into future PCS designs. This paper revisits past and present development efforts in PCS design, identifies the evolutionary improvements and describes the new opportunities for PCS designs. The new opportunities are arising from the increased availability and capability of semiconductor switching components, smart power devices, and power integrated circuits (PICS).

The term ``TNT Equivalence`` is used throughout the explosives and related industries to compare the effects of the output of a given explosive to that of TNT. This is done for technical design reasons in scaling calculation such as for the prediction of blast waves, craters, and structural response, and is also used as a basis for government regulations controlling the shipping, handling and storage of explosive materials, as well as for the siting and design of explosive facilities. TNT equivalence is determined experimentally by several different types of tests, the most common of which include: plate dent, ballistic mortar, trauzl, sand crush, and air blast. All of these tests do not necessarily measure the same output property of the sample explosive. As examples of this, some tests depend simply upon the CJ pressure, some depend upon the PV work in the CJ zone and in the Taylor wave behind the CJ plane, some are functions of the total work which includes that from secondary combustion in the air mixing region of the fireball and are acutely effected by the shape of the pressure-time profile of the wave. Some of the tests incorporate systematic errors which are not readily apparent, and which have a profound effect upon skewing the resultant data. Further, some of the tests produce different TNT Equivalents for the same explosive which are a function of the conditions at which the test is run. This paper describes the various tests used, discusses the results of each test and makes detailed commentary on what the test is actually measuring, how the results may be interpreted, and if and how these results can be predicted by first principals based calculations. Extensive data bases are referred to throughout the paper and used in examples for each point in the commentaries.

For PZT films deposited on Pt coated substrates, remanent polarization is a monotonic function of thermal expansion of the substrate, a result of 90{degree} domain formation occurring as the film is cooled through the transformation temperature. PZT film stress in the vicinity of the Curie point controls 90{degree} domain assemblages within the film. PZT films under tension at the transformation temperature area-domain oriented; whereas, films under compression at the transformation temperature are c-domain oriented. From XRD electrical switching of 90{degree} domains is severely limited. Thus, formation of these 90{degree} domains in vicinity of the Curie point is dominant in determination of PZT film dielectric properties. Chemically prepared PZT thin films with random crystallite orientation, but preferential a-domain orientation, have low remanent polarization (24 {mu}C/cm{sup 2}) and high dielectric constant (1000). Conversely, PZT films of similar crystalline orientation, but of preferential c-domain orientation, have large remanent polarizations (37 {mu}C/cm{sup 2}) and low dielectric constants (700). This is consistent with single-crystal properties of tetragonally distorted, simple perovksite ferroelectrics. Further, for our films that grain size - 90{degree} domain relationships appear similar to those in the bulk. The effect of grain size on 90{degree} domain formation and electrical properties are discussed.

MELCOR is a fully integrated, engineering-level computer code, being developed at Sandia National Laboratories for the USNRC, that models the entire spectrum of severe accident phenomena in a unified framework for both BWRs and PWRS. As part of an ongoing assessment program, the MELCOR computer code has been used to analyze a series of blowdown tests performed in the early 1980s at General Electric. The GE large vessel blowdown and level swell experiments are a set of primary system thermal/hydraulic separate effects tests studying the level swell phenomenon for BWR transients and LOCAS; analysis of these GE tests is intended to validate the new implicit bubble separation algorithm added since the release of MELCOR 1.8.2. Basecase MELCOR results are compared to test data, and a number of sensitivity studies on input modelling parameters and options have been done. MELCOR results for these experiments also are compared to MAAP and TRAC-B qualification analyses for the same tests. Time-step and machine-dependency calculations were done to identify whether any numeric effects exist in our GE large vessel blowdown and level swell assessment analyses.

The prompt neutron generation time for the Annular Core Research Reactor was experimentally determined using a prompt-period technique. The resultant value of 25.5 {mu}s agreed well with the analytically determined value of 24 {mu}s. The three different methods of reactivity insertion determination yielded {+-}5% agreement in the experimental values of the prompt neutron generation time. Discrepancies observed in reactivity insertion values determined by the three methods used (transient rod position, relative delayed critical control rod positions, and relative transient rod and control rod positions) were investigated to a limited extent. Rod-shadowing and low power fuel/coolant heat-up were addressed as possible causes of the discrepancies.

The introduction of the hazards assessment process is to document the impact of the release of hazards at the Advanced Manufacturing Processes Laboratory (AMPL) that are significant enough to warrant consideration in Sandia National Laboratories` operational emergency management program. This hazards assessment is prepared in accordance with the Department of Energy Order 5500.3A requirement that facility-specific hazards assessments be prepared, maintained, and used for emergency planning purposes. This hazards assessment provides an analysis of the potential airborne release of chemicals associated with the operations and processes at the AMPL. This research and development laboratory develops advanced manufacturing technologies, practices, and unique equipment and provides the fabrication of prototype hardware to meet the needs of Sandia National Laboratories, Albuquerque, New Mexico (SNL/NM). The focus of the hazards assessment is the airborne release of materials because this requires the most rapid, coordinated emergency response on the part of the AMPL, SNL/NM, collocated facilities, and surrounding jurisdiction to protect workers, the public, and the environment.

A review of US and Japanese experiences with using microelectronics consortia as a tool for strengthening their respective industries reveals major differences. Japan has established catch-up consortia with focused goals. These consortia have a finite life targeted from the beginning, and emphasis is on work that supports or leads to product and process-improvement-driven commercialization. Japan`s government has played a key role in facilitating the development of consortia and has used consortia promote domestic competition. US consortia, on the other hand, have often emphasized long-range research with considerably less focus than those in Japan. The US consortia have searched for and often made revolutionary technology advancements. However, technology transfer to their members has been difficult. Only SEMATECH has assisted its members with continuous improvements, compressing product cycles, establishing relationships, and strengthening core competencies. The US government has not been a catalyst nor provided leadership in consortia creation and operation. We propose that in order to regain world leadership in areas where US companies lag foreign competition, the US should create industry-wide, horizontal-vertical, catch-up consortia or continue existing consortia in the six areas where the US lags behind Japan -- optoelectronics, displays, memories, materials, packaging, and manufacturing equipment. In addition, we recommend that consortia be established for special government microelectronics and microelectronics research integration and application. We advocate that these consortia be managed by an industry-led Microelectronics Alliance, whose establishment would be coordinated by the Department of Commerce. We further recommend that the Semiconductor Research Corporation, the National Science Foundation Engineering Research Centers, and relevant elements of other federal programs be integrated into this consortia complex.

Inside this issue: (1) Robotic cleaning safer, faster, more reliable; robots taught how to clean in seconds instead of days. (2) Microporous insulating films can boost microcircuit performance; films display improved dielectric constant, mechanical properties, (3) Life-cycle analysis: the big picture; cradle-to-grave environmental analysis tailored to the needs of defense manufacturing, (4) New simulation tool predicts properties of forged metal; internal state variable model improves design, speeds development time.

This report summarizes the results from MELCOR calculations of severe accident sequences in the ABWR and presents comparisons with MAAP calculations for the same sequences. MELCOR was run for two low-pressure and three high-pressure sequences to identify the materials which enter containment and are available for release to the environment (source terms), to study the potential effects of core-concrete interaction, and to obtain event timings during each sequence; the source terms include fission products and other materials such as those generated by core-concrete interactions. Sensitivity studies were done on the impact of assuming limestone rather than basaltic concrete and on the effect of quenching core debris in the cavity compared to having hot, unquenched debris present.

An experimental technique is described to launch an intact ``chunk,`` i.e. a 0.3 cm thick by 0.6 cm diameter cylindrical titanium alloy (Ti-6Al-4V) flyer, to 10.2 km/s. The ability to launch fragments having such an aspect ratio is important for hypervelocity impact phenomenology studies. The experimental techniques used to accomplish this launch were similar but not identical to techniques developed for the Sandia HyperVelocity Launcher (HVL). A confined barrel impact is crucial in preventing the two-dimensional effects from dominating the loading response of the projectile chunk. The length to diameter ratio of the metallic chunk that is launched to 10.2 km/s is 0.5 and is an order of magnitude larger than those accomplished using the conventional hypervelocity launcher. The multi-dimensional, finite-difference (finite-volume), hydrodynamic code CTH was used to evaluate and assess the acceleration characteristics i.e., the in-bore ballistics of the chunky projectile launch. A critical analysis of the CTH calculational results led to the final design and the experimental conditions that were used in this study. However, the predicted velocity of the projectile chunk based on CTH calculations was {approximately} 6% lower than the measured velocity of {approximately}10.2 km/S.

Integrated Service digital Network, ISDN, technology is an integral component of Sandia National Laboratories telecommunications infrastructure. ISDN is a fully digital telephone service that allows simultaneous voice and data communication from the same telephone instrument. Almost all ISDN phones in use at Sandia/New Mexico and most ISDN phones at Sandia/California have a built-in module for data communication. This user guide describes the use and operation of ISDN data module and services as they are installed at Sandia.

LUGSAN (LUG and Sway brace ANalysis) is a analysis and database computer program designed to calculate store lug and sway brace loads from aircraft captive carriage. LUGSAN combines the rigid body dynamics code, SWAY85 and the maneuver calculation code, MILGEN, with an INGRES database to function both as an analysis and archival system. This report describes the operation of the LUGSAN application program, including function description, layout examples, and sample sessions. This report is intended to be a user`s manual for version 1.1 of LUGSAN operating on the VAX/VMS system. The report is not intended to be a programmer or developer`s manual.

SKYDOS evaluates skyshine dose from an isotropic, monoenergetic, point photon source collimated by three simple geometries: (1) a source in a silo; (2) a source behind an infinitely long, vertical, black wall; and (3) a source in a rectangular building. In all three geometries, an optical overhead shield may be specified. The source energy must be between 0.02 and 100 MeV (10 MeV for sources with an overhead shield). This is a user`s manual. Other references give more detail on the integral line-beam method used by SKYDOSE.

McSKY evaluates skyshine dose from an isotropic, monoenergetic, point photon source collimated into either a vertical cone or a vertical structure with an N-sided polygon cross section. The code assumes an overhead shield of two materials, through the user can specify zero shield thickness for an unshielded calculation. The code uses a Monte-Carlo algorithm to evaluate transport through source shields and the integral line source to describe photon transport through the atmosphere. The source energy must be between 0.02 and 100 MeV. For heavily shielded sources with energies above 20 MeV, McSKY results must be used cautiously, especially at detector locations near the source.

Calculations of water flow through Yucca Mountain show significant dryout and water perching in the vicinity of the proposed nuclear waste repository. These calculations also show that the extent of the dryout and perched water zones is a strong function of the material characteristics which are used to represent the fracture zones. The results show that for 100 {mu}m fracture case appreciable dryout and perched regions exist. When 1 {mu}m fractures are used no dryout or perched regions are calculated.

An integral part of the licensing procedure for the potential nuclear waste repository at Yucca Mountain, Nevada involves accurate prediction of the in situ rheology for design and construction of the facility and emplacement of the canisters containing radioactive waste. The data required as input to successful thermal and mechanical models of the behavior of the repository and surrounding lithologies include bulk density, grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensile strengths. In this study a suite of experiments was performed on cores recovered from the USW-NRG-6 borehole drilled to support the Exploratory Studies Facility (ESF) at Yucca Mountain. USW-NRG-6 was drilled to a depth of 1100 feet through four thermal/mechanical units of Paintbrush tuff. A large data set has been collected on specimens recovered from borehole USW-NRG-6. Analysis of the results of these experiments showed that there is a correlation between fracture strength, Young`s modulus, compressional wave velocity and porosity. Additional scaling laws relating; static Young`s modulus and compressional wave velocity; and fracture strength and compressional wave velocity are promising. Since there are no other distinct differences in material properties, the scatter that is present at each fixed porosity suggests that the differences in the observed property can be related to the pore structure of the specimen. Image analysis of CT scans performed on each test specimen are currently underway to seek additional empirical relations to aid in refining the correlations between static and dynamic properties of tuff.

One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property scaling is addressed. Property scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property scaling with the aim of developing and testing models that describe scaling behavior in a quantitative manner. Scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. The approach is to systematically isolate those factors believed to influence property scaling and investigate their relative contributions to overall scaling behavior. Two blocks of tuff, each exhibiting differing heterogeneity structure, have recently been examined. Results of the investigation show very different scaling behavior, as exhibited by changes in the distribution functions and variograms, for the two tuff samples. Even for the relatively narrow range of measurement scales employed significant changes in the distribution functions, variograms, and summary statistics occurred. Because such data descriptors will likely play an important role in calculating effective media properties, these results demonstrate both the need to understand and accurately model scaling behavior.

Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The ``weeps model`` now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive.

Indicator geostatistical techniques have been used to produce a number of fully three-dimensional stochastic simulations of large-scale lithologic categories at the Yucca Mountain site. Each realization reproduces the available drill hole data used to condition the simulation. Information is propagated away from each point of observation in accordance with a mathematical model of spatial continuity inferred through soft data taken from published geologic cross sections. Variations among the simulated models collectively represent uncertainty in the lithology at unsampled locations. These stochastic models succeed in capturing many major features of welded-nonwelded lithologic framework of Yucca Mountain. However, contacts between welded and nonwelded rock types for individual simulations appear more complex than suggested by field observation, and a number of probable numerical artifacts exist in these models. Many of the apparent discrepancies between the simulated models and the general geology of Yucca Mountain represent characterization uncertainty, and can be traced to the sparse site data used to condition the simulations. Several vertical stratigraphic columns have been extracted from the three-dimensional stochastic models for use in simplified total-system performance assessment exercises. Simple, manual adjustments are required to eliminate the more obvious simulation artifacts and to impose a secondary set of deterministic geologic features on the overall stratigraphic framework provided by the indictor models.

Laboratory experiments were performed to measure the effect of frequency, water-saturation, and strain amplitude on Young`s modulus and seismic wave attenuation on rock cores recovered on or near the site of a potential nuclear waste repository at Yucca Mountain, Nevada. The purpose of this investigation is to perform the measurements using four techniques: cyclic loading, waveform inversion, resonant bar, and ultrasonic velocity. The measurements ranged in frequency between 10{sup {minus}2} and 10{sup 6} Hz. For the dry specimens Young`s modulus and attenuation were independent of frequency; that is, all four techniques yielded nearly the same values for modulus and attenuation. For saturated specimens, a frequency dependence for both Young`s modulus and attenuation was observed. In general, saturation reduced Young`s modulus and increased seismic wave attenuation. The effect of strain amplitude on Young`s modulus and attenuation was measured using the cyclic loading technique at a frequency of 10{sup {minus}1} Hz. The effect of strain amplitude in all cases was small. For some rocks, such as the potential repository horizon of the Topopah Spring Member tuff (TSw2), the effect of strain amplitude on both attenuation and modulus was minimal.